Apparatus, methods, and liners for repairing conduits

ABSTRACT

An apparatus and method for repairing the juncture or intersection of a first conduit and a second conduit is disclosed. The apparatus includes a main body for transporting and positioning a repair material impregnated with a heat curable resin system or matrix. An inflation device and caul plates carried by the main body position and compress the repair material against the intersection. This includes a portion of the interior of the second conduit and flange portion in the first conduit. The inflation device and caul plates include conductive fibers that are electrically resistively heated to effect curing of the resin in the repair material. Additionally, a method and liner apparatus for the in-situ repair of conduits having large diameters is disclosed. The liner comprising a plurality of discrete heating zones, where each zone impregnated with a curable resin. Each zone further having a fiber architecture, where the fiber architecture has a plurality of conductive fibers. The liner further comprising a plurality of interface areas, each interface area located between a pair of heating zones. Each interface area is impregnated with a curable resin. Each interface area has a seam and a fiber architecture, the fiber architecture formed from a plurality of non-conductive fibers. The fiber architecture of each heating zone further comprises a plurality of non-conductive fibers. Each interface area has a plurality of cavities. The liner further comprising means for sealing the interface areas and a portion of the zones. The sealing means further insures the structural integrity of the seam. Further, a method and apparatus for forming spoolable composite pipe. The method comprises the steps of extruding thermoplastic resin to form an inner layer of a pipe. Winding a plurality of conductive fibers to form an intermediate layer, the intermediate layer positioned about the inner layer. Extruding thermoplastic resin to form an outer layer, the outer layer positioned about the intermediate layer to form a flexible multi-component pipe. Applying pressure to deform the multi-component pipe. Spooling the multi-component pipe onto a storage coil. Dispensing the multi-component pipe from the storage coil into a damaged conduit, the conduit having internal dimensions. Applying fluid pressure to the multi-component pipe to reshape the multi-component pipe. Applying current to the conductive fibers in the multi component pipe to heat form and consolidate the inner, intermediate, and outer layers into a composite pipe. Applying additional fluid pressure to further reshape the composite pipe to correspond to the internal dimensions of the conduit. The method further comprising the step of connecting electric leads to a power source and the conductive fibers in the composite pipe.

RELATED CASES

[0001] The present invention claims priority from provisionalapplication Nos. 60/179,687; 60/179,806 and 60/179,686.

DESCRIPTION

[0002] 1. Technical Field

[0003] The present invention generally relates to an apparatus andmethod for the installation of a repair material within a conduit orpipe such as a sanitary sewer line. More specifically, the inventionpertains to an apparatus and method for the installation of a repairmaterial at the intersecting junction between two transversely opposedpipes or conduits.

[0004] The present invention also relates to a method and apparatus forrepair of large diameter sanitary sewer pipe or conduit. Specifically,the invention pertains to an advanced method and liner apparatus for thein-situ repair of conduits having large diameters.

[0005] Additionally, the present invention relates to a method andapparatus for forming a spoolable composite pipe. More specifically,this invention pertains to a method for the in-situ formation ofspoolable composite pipe and the in-situ repair of damaged conduit withthe spoolable composite pipe.

[0006] 2. Background of the Invention

[0007] It is generally accepted that the aging infrastructure worldwideis fast approaching originally designated design lives. Specifically,pipes and conduits located both above and below ground employed in theconveyance of liquids frequently require repair to prevent leakage intothe system as well as preventing fluid from the leaving the system. Thecause of leakage can vary from improper installation to environmentalconditions to normal aging or the detrimental effects of the substancestransported on the pipe materials. Regardless of the cause, leakage isundesirable. The United States Congress and the US EnvironmentalProtection Agency have both mandated reductions in such leakage throughsuch means as the Clean Water Act.

[0008] Because of the high costs and the level of difficulty involved inexcavating or removing and replacing leaking conduits, various methodshave been devised for insitu repair. These methods have minimized theexpense and hazards associated with digging and replacing defectivepipes.

[0009] In the conventional processes for the insitu rehabilitation ofexisting pipes and conduits, a flexible tubular liner impregnated with athermosetting synthetic resin matrix is introduced into the conduitusing an inverting process as well know to one skilled in the art. InU.S. Pat. No. 5,108,533, the flexible tubular liner is comprised of aneedle-punched felt material. In conditions where the intersectingangles of the main pipe and the lateral pipe constitute an obtuse angle,as typically encountered in a convention sewer “wye”, a needle-punchedfelt material does not possess the necessary flexibility to conform wellto the surrounding pipe walls.

[0010] Once the liner is positioned within the pipeline, the liner ispressurized internally using a fluid pressure such as air or water toforce the lining material into intimate contact with the pipe interiorand provide compaction. Adding heat in the form of hot water, steam orelectrical energy can then cure the resin matrix. The latter method ofproviding heat by electrical energy is disclosed in U.S. Pat. No.5,606,997. Once the resin is cured, the resultant material forms a hard,tight fitting lining within the pipe that also serves to provide addedstructural support.

[0011] In the repair of sanitary sewer systems for instance, a maintrunk line is used for the transportation of effluent from variousintersecting piping systems to an end location. The majority of work todate has focused on the repair and rehabilitation of the main trunklines. Even after much effort and expense has been expended on theremediation of these systems, the areas of confluence between the mainlines and intersecting side lines (hereinafter called laterals) has onlyminimally been addressed. In a typical municipal sewer system, aplurality of laterals can exist in every mainline section. With as manyas 10 laterals on a typical residential street, the potential for fluidingress and egress at the lateral to main interface is great.

[0012] Only several processes are known that address repair of thelateral to main interface. One such process is described in U.S. Pat.No. 5,223,189 wherein a thermoplastic sealing bushing including aninternal heating element is installed into the lateral opening fromwithin the mainline by means of a robotic device and an expandablemandrel. This method relies on a heat formed seal being produced betweenthe bushing and a pipeline lined with a similar, compatiblethermoplastic material. In U.S. Pat. No. 5,950,682, a resin absorbentmaterial, impregnated with a hardening resin matrix, is positionedwithin the mainline pipe and provides a means for inverting a section oflike material into the lateral pipe for a pre-determined distance.Because these systems and, systems similar to this use a resin matrixthat is expected to fully cross-link or cure in an undesirableenvironment (i.e. hot, cold, wet, etc), catalysts, initiators and eveninhibitors are added to the resin system in an attempt to control thecuring mechanism. This has resulted in many failures due to prematurecuring of the resin, inadequate resin cross-linking and shrinkage. Inaddition, because the resin is applied to the repair material at theinstallation site, inconsistencies in both resin content and mixingprocedures can be expected. Other methods have been disclosed that usean auxiliary curing source unlike the typical systems that rely solelyon ambient temperatures to effect a cure. Radiant energy in the form ofultraviolet light, as in U.S. Pat. No. 5,915,419, or visible light, asdisclosed in U.S. Pat. No. 4,518,247 have been employed to provide acuring mechanism for lateral interface sealing systems. The shortcomingsof these types of systems lay in the difficulty of the prescribedradiant light source to penetrate through the thickness of the repairmaterial and the overall fragility of such devices.

[0013] Therefor, it is desirable to provide a system to overcome theconstraints mentioned above and also afford a fast, consistent repairmethod that enables robust, cost effective reconstruction of the lateralto mainline interface.

[0014] Another problem is encountered with repairing pipes having largediameters. Various methods exist for rehabilitating damaged sanitarysewer conduits with diameters exceeding about eighteen inches. Thesemethods include physical removal of the damaged section of the conduit,and replacement of the damaged section. A more common method is the useof a reinforced liner having dimensions similar to the dimensions of thedamaged portion of the conduit.

[0015] Liners are typically formed from composite materials and can beimpregnated on-site, or pre-impregnated with a curable resin. When theresin is cured, it hardens and the liner forms a protective shell in thesection of the conduit where it is placed. There are two primary methodsto cure the resin, ambient cure and heat activated cure, including hotwater or steam cure.

[0016] Ambient curing suffers from a number of disadvantages. If theambient temperature is too low, which is common with undergroundconduits, the resin will not completely cure and the liner can collapse.In contrast, if the ambient temperature is too high, the resin can cureprematurely, that is before the liner is properly located in the damagedportion of the conduit.

[0017] There are a number of disadvantages to curing a liner with hotwater or steam. First, the equipment required to heat the water or tocreate steam is extremely expensive and inefficient. Second, curing witheither fluid requires a temperature ramp-up, which consumes long periodsof time. For example, the water temperature must be held atapproximately 135° F. for several hours, and then increased to 180° F.for several more hours. For a ninety-six (96) inch conduit, the curingprocess can last between three to seven days.

[0018] Curing a liner with hot water, steam, or ambient is alsonegatively affected by heat sink in the conduit. The heat sink isgreater on the lower portion of the conduit than on the upper portion ofthe conduit. This result occurs because the lower portion is typicallywet, while the upper portion remains dry. This is especially true in agravity conduit that is not fully charged. The wet lower portion of theconduit draws a greater amount of heat, q, from the heat source thandoes the dry upper portion. The heat flux, q″, in the lower portion ofthe conduit is greater than the heat flux in the upper portion of theconduit. As a result, a greater quantity of heat is required to cureliner in the lower segments of the conduit than liner in the uppersegments of the conduit. In addition, heat sink can prevent the completecuring of all resin in the liner, thereby reducing the strength anddurability of the liner. These factors reduce both the cost efficiencyand process efficiency of hot water, steam, and ambient cure.

[0019] The conventional liners used to repair large diameter conduitsare very thick and generally require a large amount of resin. The largeamount of resin exacerbates the need for ramped temperatures and as aresult, further increases curing times while reducing the efficiency ofthe repair. Due to their large size and weight, liners for largediameter conduits are difficult to handle and maneuver within thedamaged conduit. Also, liners for large diameter conduits are moresusceptible to the negative effects of heat sink.

[0020] One aspect of the present invention is provided to solve theseand other problems.

SUMMARY OF THE INVENTION

[0021] In one embodiment the present invention is directed to anapparatus for repairing an intersection between a first conduit and asecond conduit. The apparatus comprises a body or support structure fortransporting repair material containing a heat curable resin to theintersection of the first conduit and the second conduit. The repairmaterial is structured to conform to the shape of the intersection. Thebody includes an inflation device that is connected to and carried bythe body. The inflation device is capable of compressing the repairmaterial to at least a portion of the intersection. For example, theinflation device may be a tubular inflatable bladder that compresses aportion of the repair material against the interior of the secondconduit adjacent the intersection. The inflation device includesconductive fibers capable of electrically resistively heating theinflation device to effect curing of the resin in the repair material.These fibers could be metallic or may be of a non-ferrous material.

[0022] The apparatus may further comprise a first caul plate, or wingstructure connected to the body. The first caul plate is moveable from aretracted position (which facilitates movement of the body through thefirst conduit) to an extended position to compress a portion of therepair material against the first conduit to form a flange proximate theintersection. A second similar caul plate can also be connected to thebody. The caul plates may include conductive fibers capable ofelectrically resistively heating the caul plates to facilitate curing ofthe flange portion of the repair material.

[0023] The apparatus may further comprise skid plates connected to thebody to assist in positioning the apparatus at the proper location inthe first conduit. Additionally, the body of the apparatus may furtherinclude a lift mechanism, for example, a lift cylinder, to facilitatepositioning of the repair material against the intersection.

[0024] In a separate embodiment, the invention comprises an apparatusfor repairing an intersection of a first conduit and a second conduithaving a support structure for transporting and positioning a repairmaterial impregnated with a heat curable resin at the intersection ofthe first conduit and the second conduit. The support structure housesan inflatable bladder having a plurality of conductive fibers forelectrically generating resistive heat to facilitate curing of the resinimpregnated in the material.

[0025] The apparatus further includes a first line connected to thesupport structure for providing fluid pressure, from a source of fluidpressure, to inflate the bladder, and a second line connected to thesupport structure for providing electrical energy, from a power source,to the conductive fibers in said bladder.

[0026] The apparatus may further comprise a wing formation connected tosaid support structure to compress a flange portion of the repairmaterial at said intersection. The wing structure preferable includesconductive fibers for electrically generating resistive heat tofacilitate curing of the flange portion of the repair material. Theapparatus may further include a lift mechanism to facilitate positioningof the repair material at the intersection.

[0027] In another embodiment of the invention a method of repairing anintersection of a first conduit and a second conduit is disclosed. Themethod comprises providing a repair material configured to conform to anintersection of a first conduit and a second conduit, impregnating therepair material with a heat curable resin, positioning said repairmaterial at the intersection, compressing the repair material againstthe intersection with a structure having a plurality of electricallyconductive fibers, and applying an electric current to the conductivefibers to resistively heat the fibers to facilitate curing of the resinin the repair material.

[0028] The method may further include providing an inflatable bladderfor compressing the repair material against the intersection, andinflating the bladder. Additionally, the method may further compriseforming a flange in the repair material, and compressing the flangeagainst a portion of said first conduit proximate the intersection.

[0029] The interface or intersection sealing apparatus of the presentinvention allows for a structural, pre-impregnated, flanged compositerepair collar to be efficiently positioned and cured in place. The curedcomposite to provide the restoration of the connection between a mainline conduit and an intersecting line. The apparatus is equipped with aninflation/heating device, which is capable of inverting the repairmaterial into the lateral line, and an articulated, heated caul platethat firmly compresses the flanged portion of the material within themainline. The integral heating system comprises two differentiallycontrolled heating assemblies containing an array of electricallyconductive fiber heating elements embedded in both constructions togenerate heat for cure. The device further provides a launching platformto safely transport and position the repair material and house theelectro-pneumatic and electrical components for the separate operationof the inflatable components and the mechanical motion components. Therepair materials used are all pre-impregnated off-site in a controlledenvironment, heat activated and stable at ambient temperatures thereforeeliminating premature cross-linking of the resin matrix before therepair is satisfactorily positioned, and ensuring thorough andconsistent resin wet-out. Because of the localized concentration ofapplied heat, cure cycles can be as fast as 15 minutes, depending onresin systems used, without disturbing surrounding areas.

[0030] According to an object of another embodiment of the invention, aliner is provided for repairing damage in large diameter conduits. Theliner comprises a plurality of discrete heating zones and a plurality ofinterface areas. Each heating zone is impregnated with a heat curableresin. Each zone has a fiber architecture formed from the combination ofa plurality of conductive fibers and non-conductive fibers. Preferably,the conductive fibers are carbon fibers, which also give the fiberarchitecture high strength qualities.

[0031] Each interface area is located between a pair of heating zones,and each area is impregnated with a heat curable resin. Each interfacearea has a fiber architecture formed from a plurality of non-conductivefibers. The ends of two heating zones abut at a seam within eachinterface area.

[0032] The liner further includes a hybrid tape that is placed about theinterface area and the heating zones. The hybrid tape helps to preventfracture or rupture of the seam. The hybrid tape is formed from theconsolidation of two outer layers formed from non-conductive fibers andan inner layer formed from conductive fibers. The hybrid tape can beused to cure the resin in the interface area.

[0033] Another object of this invention is a method of applying currentvia leads to the heating zones in the liner to cure the resinimpregnated therein. Current can be applied to individual heating zones,or in a sequential manner to heating zones to effectuate a preciselycontrolled and efficient cure cycle. Alternatively, current can beapplied to the heating zones and the hybrid tape to cure the resin.

[0034] In a further embodiment, the in-situ repair of a conduit can beeffectuated by a fiber reinforced thermoplastic (“FRP”) composite pipewith multiple layers. According to an aspect of the invention, thecomposite pipe results when the discrete layers in multi-component pipeare heat formed and consolidated. The multi-component pipe comprises aninner layer of thermoplastic resin, where the inner layer is formed froman extrusion process. An outer layer of thermoplastic resin, where theouter layer is formed from an extrusion process. An intermediate layerhaving a fiber architecture, where the fiber architecture is formed fromwinding a plurality of conductive fibers. The conductive fibers arepreferably carbon fibers. The fiber architecture includes a plurality ofnon-conductive fibers. The conductive fibers and the non-conductivefibers are commingled with a plurality of thermoplastic filaments.

[0035] According to another aspect of the invention, the multi-componentpipe comprises an inner layer of thermoplastic resin, where the innerlayer is formed from an extrusion process. An outer layer ofthermoplastic resin, where the outer layer is formed from an extrusionprocess. An intermediate layer formed from conductive tape, where theconductive tape has a plurality of conductive fibers. The conductivetape can be wrapped, woven, stitch-bonded, or needle-punched about anouter surface of the inner layer. The intermediate layer can include aplurality of thermoplastic fibers. The intermediate layer can include aplurality of non-conductive fibers, the non-conductive fibers commingledwith plurality of thermoplastic filaments.

[0036] According to another aspect of the invention, a method ofrepairing a damaged conduit with a composite pipe comprises extrudingthermoplastic resin to form an inner layer of a pipe; winding aplurality of conductive fibers to form an intermediate layer, theintermediate layer positioned about the inner layer; and, extrudingthermoplastic resin to form an outer layer, the outer layer positionedabout the intermediate layer to form a flexible multi-component pipe.Additionally, the method includes applying pressure to deform themulti-component pipe; spooling the multi-component pipe onto a storagecoil; dispensing the multi-component pipe from the storage coil into adamaged conduit, the conduit having internal dimensions; applying fluidpressure to the multi-component pipe to reshape the multi-componentpipe; applying current to the conductive fibers in the multi-componentpipe to heat form and consolidate the inner, intermediate, and outerlayers into a composite pipe; and, applying additional fluid pressure tofurther reshape the composite pipe to correspond to the internaldimensions of the conduit. The method further comprises the step ofconnecting electric leads to a power source and the conductive fibers inthe composite pipe.

[0037] Further aspects of the invention are disclosed in the detaileddescription of the preferred embodiment, the drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Embodiments of the invention will be described with the aid ofthe following diagrammatic drawings.

[0039]FIG. 1 is a side view of the apparatus of the present invention ina main line adjacent to an intersecting lateral line;

[0040]FIG. 2 is an end view of the apparatus of FIG. 1;

[0041]FIG. 3 is a partial cross-sectional side view of the apparatus ofthe present invention detailing the internal workings of the apparatus;

[0042]FIG. 4 is a cross-sectional end view of the apparatus;

[0043]FIG. 5 is a side view depicting the apparatus with the carriageextended and inflation bladder inverted into a lateral line;

[0044]FIG. 6 shows an enlarged end view of the apparatus of FIG. 5placing the repair material in an intersecting lateral line;

[0045]FIG. 7 is a side view of the apparatus of the present inventiondemonstrating the repair material loading process;

[0046]FIG. 8 is a simplified, cross-sectional end view; enlarged toillustrate the actuator arm assembly of the apparatus;

[0047]FIG. 9 is a perspective view of a liner according to theinvention;

[0048]FIG. 10 is a partial cross-sectional view of the liner of FIG. 9,showing a plurality of heating zones and an interface area;

[0049]FIG. 11 is a partial cross-sectional view of the liner of FIG. 9showing a hybrid tape overlapping the interface area and a portion ofthe heating zones;

[0050]FIG. 12 is a perspective view of a composite pipe according theinvention;

[0051]FIG. 13 is a cross-sectional view of a multi-component pipe,showing a plurality of commingled conductive fibers and non-conductivefibers;

[0052]FIG. 14 is perspective view of an alternate embodiment showing aflexible intermediate layer;

[0053]FIG. 15 is a schematic diagram of the process used to form thecomposite pipe of FIG. 12;

[0054]FIG. 16 is end view of an alternate embodiment showing a flexiblemulti-component pipe; and,

[0055]FIG. 17 is a partial cross-sectional view of an alternateembodiment showing a multi-component pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0056] While this invention is susceptible of embodiments in manydifferent forms, there is shown in the drawings and will herein bedescribed in detail preferred embodiments of the invention with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the broad aspect of the invention to the embodimentsillustrated.

[0057] Conduit Intersection Repair:

[0058] A preferred embodiment of the apparatus of the present inventionis depicted in FIG. 1. In accordance with the invention, the apparatusincludes a main body 1 that is positioned in a first conduit 15. Thefirst conduit 15 may be pipe forming a main line of a sewer system. Themain line 15 intersects a second conduit or lateral line 8. Lateral line8 is shown here in a perpendicular position essentially at a 90° angleto the main line pipe and intersects the main line pipe at the topportion. This condition is typical but may also be arranged in otherconfigurations. For example, the lateral pipe may intersect the mainline pipe at ±45° and can be located radially anywhere from the nineo'clock position to the three o'clock position.

[0059] Repair material 7 is loaded into the apparatus in preparation forinsertion at the intersection of the main line and lateral line. Repairmaterial 7 is preferably constructed of a reinforcing material capableof holding a heat hardenable or formable resin matrix. Material 7 isalso constructed of a material that would be expected to include aportion 7 a that conforms to the interior geometry of the lateral pipewall, and be flexible enough to provide a flange face 7 b in the mainline pipe.

[0060] Radial and vertical positioning of the apparatus is achievedremotely using appropriate controls, and communicated to the apparatusthrough an umbilical 11. The entire assembly is delivered to the pointof repair using a winch or similar device attached the unit via cableassemblies 13.

[0061] In FIG. 2, the apparatus is shown again in a typical condition.Heated caul plates 5 are shown in a retracted position on an upperportion of the body 1 of the apparatus, affording a minimal crosssection and allowing passage into a main line that may contain offsets,protrusions, etc. The caul plates 5 (herein after referred to as“wings”) are articulated to allow this reduced cross section by the useof hinges 23.

[0062] In FIG. 7, the method for loading the repair material 7 isillustrated. Applying a fluid pressure to the body 1 through umbilical11 pressurizes an inflation device in the form of a bladder 22. Thisfluid pressure is regulated through the use of electro-pneumaticregulators located in rear housing 6 in the body 1, and controlledremotely through signal wires in umbilical 11. Pressure sensing isaccomplished by sending units located within main body 1 and transmittedthrough umbilical 11. All of the signal wires in umbilical 11 terminateat an operator interface control station. The force required during thisstep in minimal and sufficient to cause the bladder 22 to rigidize.

[0063] The repair material 7 is constructed in such a fashion as toincorporate both the tubular lateral lining portion 7 a as well as theflanged area 7 b without the undesirable effect of a potentially weakseam at the transition from tubular to planar. With the bladder 22pressurized, the material 7, pre-impregnated with a resin, is wrappedaround the extended bladder 22 and caused to lay flat on the surface ofthe wings 5. Depending on the structural requirements, layers ofmaterial 7 can continue to be plied to achieve the desired strengths.With the lay-up complete, the internal pressure inside the bladder 22 islowered to facilitate inversion into the main body 1 of the apparatus.As shown in FIG. 3, a spindle 20 capable of rotation is fixably attachedwithin the body 1 at a posterior location. The spindle is sealed fromthe atmosphere by the use of o-rings and protrudes slightly from thebody 1 to allow attachment of a tool to cause rotation.

[0064] As shown is FIG. 5, the bladder construction contains an internaltether 16 that is permanently attached to the interior of the bladder atfitting 21 and removably attached to spindle 20 within the main body 1.To invert the bladder 22 and repair material 7 into the main body forsafe transport to the repair location, the tether is wound about thespindle causing the bladder to retract. With the repair material loadedinto the device, a winch, or similar device is employed to pull theapparatus to the desired location within a pipeline. A closed circuittelevision camera (not shown) can be used to assist in determining thecorrect location and positioning. Once the entire assembly has beensatisfactorily located in proximity to the repair area, finalpositioning commences via remote control.

[0065]FIG. 5 shows the internal workings of the apparatus. In order tofacilitate rotary positioning, the apparatus contains a poweredrotational mechanism located in rear housing 6. The rotation mechanismis attached to the main body 1 by use of a coupling. The front section12 of the body 1 contains a rotary bearing to compliment this action.Skids 14 are attached to both the front 12 and rear 6 sections to affordminimal surface contact with the main line pipe and ease pulling forcesrequired.

[0066] With the device appropriately positioned radially, vertical liftis accomplished using lift cylinders 2. The lift cylinders can beactuated with compressed air or hydraulically using a suitable medium.These cylinders are firmly attached to front section 12 and rear section6 with the cylinder rams attached to the main body 1. When activated,the cylinders effectively lift the main body to force the top portion ofthe caul plate to be in contact with the interior wall of the main linepipe at the area surrounding the lateral pipe opening. As the main bodylifts, actuator arms 3 encounter the main line pipe wall, as depicted inFIG. 6. In FIG. 7, the actuator arm bearings 3 convert the verticalmotion to a lifting motion through a fulcrum 25 attached to the mainbody 1. The opposite ends of the actuator arms 26 are positioned underthe wings 5 and cause the wings to unfold and compress the flanged area7 b of the repair material 7 firmly against the main line pipe walls.

[0067] By introducing pressure to the interior of the main body 1through umbilical 11, the bladder 22 and repair material 7 is caused toinvert into the lateral pipe 8. Increasing the pressure inside thebladder causes the tubular section of the repair material to conform tothe inside geometry of the lateral pipe section.

[0068] The bladder 22 and the caul plates 5, are constructed of atemperature resistant material and contain within the outer skinsurface, electrically conductive fibers that are employed to produceheat when an electrical current passes through the fibers. The materialsurrounding the conductive fibers is a flexible, resilient substancesuch as silicone, fluorosilicone or fluoropolymer. Electrical wires 17conduct the electrical energy from remotely stationed, controllablepower supplies to the electrically conductive fibers. Heatingtemperatures produced range from 200° F.-400° F. depending on the curingrequirements of the resin matrix selected for use in the repair material7. These temperatures can be achieved in as little as 10 minutesenabling an extremely fast cure cycle.

[0069] The bladder 22 is detachable from the main body to facilitatereplacement or to switch to a bladder of different length and/ordiameter. When the desired temperatures have been achieved and curecycle complete, the apparatus can be removed from the pipeline andloaded again with repair material for an additional repair. With theability to quickly produce and control heat, multiple repairinstallations are completed in a short time frame.

[0070] To remove the apparatus from the pipeline, steps include firstremoving electrical power from the conductive fibers in both the bladderand caul pads. Next, the pressurized interior of the main body 1 andbladder 22 is introduced to vacuum. A venturi type vacuum pump 10, whichproduces vacuum from a pressurized air supply, is housed within the mainbody 1. Electro-pneumatic solenoid valves located in the rear section 6switch the supply of pressurized air delivered by umbilical 11 from theinterior of the main body and redirect this air supply to the venturivacuum. This application of vacuum quickly and completely evacuates allair from within the bladder 22 and causes the bladder 22 to collapse onitself, releasing contact from the completed repair material and theinterior surfaces of the lateral pipe. Continued application of vacuumalso causes the bladder 22 to retract back into the main body.

[0071] Lift cylinders 2 are double acting in that the fluid pressureapplied to cause lift can be switched to cause the cylinder rams toretract. This switching is also accomplished through the use ofelectro-pneumatic valves located in rear housing 6. As the cylindersretract and lower the main body, the actuator arm bearings 3 are removedfrom contact with the main line pipe wall. Torsion springs located bothin the actuator arm fulcrum blocks 25 and the wing hinges 26 cause thewings to retract to the original folded position. This ensures that theentire device again assumes a smaller cross section allowing egress fromthe main line pipe.

[0072] Large Diameter Pipe Liner:

[0073]FIG. 9 shows a liner 110 for repairing damage in large diameterconduits, typically those with a diameter exceeding about eighteen (18)inches. The liner 110 is formed to be generally cylindrical or tubular.Once formed, the liner 110 has a length L, a diameter D, and athickness, t.

[0074] In FIG. 10, a partial cross-section of the liner 110 is shown.There, the liner 110 comprises a plurality of discrete heating zones 112and a plurality of interface areas 114. Each heating zone 112 extendslengthwise through the liner 110, and each zone 112 a circumferentialdimension. Each heating zone 112 is impregnated with a curable resin116, and has a fiber architecture 118. The resin 116 can be of thethermoset or thermoplastic variety. The fiber architecture 118 or fiberstructure of the heating zones 112 is formed from the combination of aplurality of electrically conductive fibers 120 and a plurality ofnon-conductive fibers 122. Alternatively, the fiber architecture 118 ofthe heating zones 112 can be formed from only conductive fibers 120.

[0075] Preferably, the conductive fibers 120 are carbon fibers becausethey provide great strength to the liner 110; however, other conductivefibers are feasible. The non-conductive fibers 122 are synthetic fibers,such as polyester, polyethylene, nylon, or fiberglass. Glass fibers canalso be used in combination with carbon and polyester fibers.

[0076] A number of different mechanical consolidation techniques can beused to form the fiber architecture 118 of the liner 110. Theseconsolidation techniques include weaving, needling (needle punching), orstitch-bonding the conductive fibers 120 and non-conductive fibers 122.In addition to mechanical consolidation, the fiber architecture 118 canbe formed by chemically consolidating the fibers 120, 122 under vacuumpressure. With any of these consolidation techniques, the filaments ofconductive fibers 120 and non-conductive fibers 122 are combined to formthe fiber architecture 118.

[0077] As shown in FIG. 10, once the consolidation technique iscompleted, the liner 110 has an fiber architecture 118 with a pair ofouter layers 124 of predominantly non-conductive fiber 122 and an innerlayer 126 of predominantly conductive fibers 120. Described in adifferent manner, the two layers 124 of non-conductive fibers 122surround, or envelop the layer 126 of conductive fibers 120. Regardlessof the consolidation technique, curable resin 116 permeates the outerlayers 124.

[0078] Electric leads can be connected to each of the discrete heatingzones 112 such that current can be applied to the heating zones 112 viathe leads to cure the resin 116. Specifically, current can be applied ina controlled, sequential manner through the leads to the conductivefibers 120 in each of the heating zones 112 to heat and cure the resin116. Because the current can be applied in a controlled manner, the curecycle of the resin 116 can be closely and efficiently monitored.

[0079] The interface area 114 is a portion of the liner 110 which islocated between a pair of heating zones 112. Each interface area 114extends lengthwise through the liner 110, and each interface area 114has a circumferential dimension. Like the heating zones 112, theinterface area 114 is impregnated with a curable resin 116, and has afiber architecture 128. The resin 116 in the interface area 114 issimilar to the resin in the heating zones 112. The fiber architecture128 or fiber structure of the interface area 114 is formed from aplurality of non-conductive fibers 122. Preferably, no conductive fibers120 are used to form the interface area 114. The non-conductive fibers122 are synthetic fibers, such as polyester, polyethylene, nylon, orfiberglass. Glass fibers can also be used in combination with polyesterfibers.

[0080] The fiber architecture 128 of the interface area 114 can beformed from any of the mechanical or chemical consolidation techniquesdescribed above. With any of these consolidation techniques, the fiberarchitecture 128 does not include conductive fibers.

[0081] As shown in FIG. 10, the interface area 114 is characterized bythe tapering of the liner 110. Two portions of the heating zone 112taper to meet at a seam 130 in the interface area 114. At the seam orborder 130, two opposing end portions of the heating zone 110 are joinedtogether. The seam 130 can be formed by needle-punching orstitch-bonding. Since the liner 110 tapers, a dielectric cavity 132 isformed in the interface area 114 on each side of the seam 130. Becausethe fiber architecture 128 of interface area 114 does not includeconductive fibers, the cavity 132 represents an absence of conductivefibers. The size and shape of the cavity 132 can vary depending upon theconfiguration of the seam 130 and the technique used to form the seam130.

[0082] The number and dimensions of the discrete heating zones 112 canvary with the size of the conduit needing repair. For example, a liner110 for use in repairing a twenty-four (24) inch diameter conduit canhave between two to four heating zones 112, depending on the dimensionsof the zones 112. The zones 112 are spaced apart and disposedcircumferentially throughout the liner 110. If the circumferentialdimensions of the heating zones 112 are relatively large, then the liner110 will have less zones 112. Conversely, if the circumferentialdimensions of the zones 112 are relatively small, then the liner 110will have more zones 112. The liner 110 is suitable for use in repairingconduits with diameters up to and including one-hundred and eight (108)inches.

[0083] Similarly, the number and dimensions of the interface areas 114can vary with the size of the liner 110 used to repair a conduit.Generally, the interface area 114 should be integral and continuous,meaning that it spans the entire length L of the liner 110. Preferably,the circumferential distance of the interface area 114 should be atleast two (2) inches; however, that dimension can vary with the size ofthe liner 110 and the diameter of the conduit needing repair. If theinterface area 114 is not properly formed or maintained, electriccurrent can arc from one heating zone to an adjacent heating zone.Typically, the arcing is uncontrollable and negatively affects the resincure cycle.

[0084] The liner 110 further includes a means for sealing the interfaceareas 114 and the heating zones 112. This is accomplished by applying atape over a portion of the interface area 114 and the heating zones 112.Referring to FIG. 11, the preferred sealing means is a hybrid tape 134placed about the interface area 114 to ensure the structural integrityof the interface area 114 and the seam 130. The hybrid tape 134 ispreferably formed from the combination of layers of non-conductivefibers 136 and conductive fibers 138. The non-conductive fibers 136 canbe synthetic fibers, such as polyester, polyethylene, nylon, orfiberglass. The conductive fibers 138 are carbon fibers, which increasethe strength of the hybrid tape 134 and prevent failure of the seam 130.

[0085] The hybrid tape 134 is flame laminated, or fused (calendared) toa portion of the interface area 114 and the heating zone 112.Alternatively, the hybrid tape can be resistively heated under pressureby passing a current through it to secure it in the appropriatelocation.

[0086] As shown in FIG. 11, two separate segments of hybrid tape 134 areused to seal the interface area 114 and seam 130. A first hybrid tape134 a is positioned in close proximity to an upper surface of the liner110, and a second hybrid tape 134 b is positioned in close proximity toa lower surface of the liner 110. Once the tapes 134 a, 134 b areproperly positioned, the tapes can be joined to the interface area 114and heating zones 112 in either of the manners discussed above. Althoughtwo distinct hybrid tapes 134 a, 134 b are shown, a single hybrid tape134 of sufficient size and strength can be used to seal the interfacearea 114 and the zones 112.

[0087] The hybrid tape 134 can be configured to overlap the interfacearea 114 and a portion of the adjacent heating zones 112, or it can beconfigured to cover only the interface area 114. In eitherconfiguration, the hybrid tape 134 can prevent rupture or failure of theseam 130.

[0088] Electric leads can be connected to each of the hybrid tape 134such that current can be applied to the hybrid tape 134 to cure theresin 116 in the interface areas 114. Specifically, current can beapplied in a controlled, sequential manner through the lead to theconductive fibers 138 in each of the hybrid tape 134 to heat and curethe resin 116 in the interface area 114. Since the current can beapplied in a controlled manner, the cure cycle of the resin 116 can beclosely and efficiently monitored.

[0089] Alternatively, when leads are not used to apply current directlyto the hybrid tape 134, the resin 116 in the interface area 114 can becured from the heat generated in and transferred from the conductivefibers 120 in the adjacent heating zones 112.

[0090] The present invention also provides a method for repairing largediameter conduits with a liner 110 generally having a plurality ofheating zones 112 and interfaces areas 114, which permit controlled andlocation specific application of current to cure resin 116 in the liner110.

[0091] The method involves the following steps. Providing a liner 110having a plurality of heating zones 112, where each zone is impregnatedwith a curable resin 116. Each zone 112 has a fiber architecture 118formed from the combination of conductive fibers 120 and non-conductive122. The liner 110 further having a plurality of interface areas 114where each interface area 114 is located between a pair of zones 112.Each interface area 114 is impregnated with a curable resin 116, andeach interface area 114 has a fiber architecture 128 formed from aplurality of non-conductive fibers 122. The liner further having a meansfor sealing the interface areas 114 and portions of the zones 112. Thesealing means is preferably a hybrid tape 134 which is secured to theliner 110 proximate the interface area 114 and portions of adjacentzones 112 to ensure the integrity of the seam 130 in the interface area114.

[0092] Electric leads can be connected to each of the zones 114, or acombination of zones 114. Also, electric leads can be connected to eachof the hybrid tapes 134, or a combination of tapes 134.

[0093] Once the damaged section of the conduit is properly evaluated,the liner 110 is placed within the damaged portion of the conduit. Next,current is supplied to various heating zones 112 in the liner 110 viathe leads. Depending upon the configuration of the leads, current can beapplied to a single heating zone 112 or to multiple heating zones 112.The current is used to cure the resin 116 in the heating zones 112 andin the interface areas 114 through resistive heating. The order ofcurrent application can be varied such that current is appliedsequentially to each of the heating zones 112. After the resin 116 inthe liner 110 is cured, the electric leads can be removed from theirconnection point.

[0094] Once the liner 110 is positioned near the damaged portion of theconduit, an inflatable bladder can be used to press the liner 110against the inner surface of the conduit. A power source is activated togenerate a sufficient electric current through the leads and the liner110 to resistively heat the liner 110 and cure the heat activated resin116. It has been found that 0.5-1.0 amps per bundle of conductive fibers120 is sufficient to cure the resin 116. Alternatively, using 5 voltsper foot (lengthwise) of the liner 110 is suitable to cure the resin116.

[0095] The current travels from a first lead to a first end of thelining 110, and longitudinally down the lining 110 through theconductive fibers 120 to a second end of the lining 110. The currentthen travels longitudinally from the second end of the lining 110 to thefirst end of the lining 110 through the conductive fibers connected to asecond lead. The current then travels through the second lead to thepower source to complete the circuit.

[0096] The custom curing of resin in various zones 112 negates theproblems of heat sink, which is very common in large diameter conduit.When heat sink occurs in large diameter conduits, the curing cycle timesfor various portions of the liner can increase dramatically. When thecuring cycle times increase, the operating and labor costs increase andthe efficiency of the curing cycle is decreased.

[0097] The customized current application method described above reducesthe curing cycle time and provides a high degree of control over theresin 116 because current can be applied in a series of controlled stepsto various zones 112. By sequentially curing the resin 116 in thediscrete zones 114, there is an appreciable reduction in the cure cycletime. In addition, the power source and the energy requirements arereduced. Curing liners by this method also reduces the equipment costsand labor costs.

[0098] The liner 110 can be used to repair large diameter conduits thatare both horizontally and vertically positioned. Also, the liner 110 canbe used to repair conduits that are positioned in the ground at an angleor incline. In addition, the liner 110 can be used to repair portions ofconduits that are angled (non-linear), where the angle ranges between0-90 degrees.

[0099] Spoolable Composite Pipe

[0100]FIG. 12 shows a fiber reinforced thermoplastic composite pipe 210used to repair damaged conduit. The composite pipe 210 is spoolable,meaning that it can be wrapped around and stored on a round spool. Thecomposite pipe 210 is generally cylindrical or tubular, and has alength, L, a diameter, D, and a thickness, t. The composite pipe 210 isformed from a plurality of flexible layers. Electric current is appliedto a resin in the layers to resistively heat form and consolidate thelayers. The composite pipe 210 results once the layers are fully heatformed and consolidated. Prior to current being applied, the layers arepositioned or nested such that they form a multi-component pipe 220.

[0101] Referring to FIG. 13, the multi-component pipe 220 includes atleast an inner layer 222, an intermediate layer 224, and an outer layer226. The flexible inner layer 222 is formed from extruding resin into agenerally cylindrical, or tubular shape. The resin in the inner layer222 is thermoplastic resin. The thickness of the inner layer 222 varieswith the conduit diameter, and the inner layer 222 configurations rangebetween SDR60 to SDR32.5.

[0102] The flexible intermediate layer 224 is formed from a windingprocess. As a result of the winding process, the intermediate layer 224has a fiber architecture formed from a plurality of commingledconductive fibers 228 and thermoplastic fibers. The intermediate layer224 is positioned about an outer surface of the inner layer 222 suchthat it is in intimate contact, or close proximity to the outer surfaceof the inner layer 222. Preferably, the conductive fibers 228 are carbonfibers. The fiber architecture of the intermediate layer 224 can includea plurality of commingled non-conductive fibers 230, which can be glassor aramid (kevlar). In addition, the conductive and/or non-conductivefibers can have thermoplastic filaments, in a composition of up to 50percent. The intermediate layer 224 can also include a plurality ofcommingled synthetic fibers. The synthetic fibers can be polyesterfibers, nylon, spectra, polyethylene or polyvinyl chloride. Thenon-conductive fibers 230 and the synthetic fibers can enhance thebonding between the layers 222, 224, 226 and the strength of the layers.

[0103] Referring to FIG. 14, the flexible intermediate layer 224 can bealternately formed from conductive tape 232 having a plurality ofconductive fibers 234 and a plurality of thermoplastic fibers 236. Theconductive fibers 234 can be located in the inner surface 238 of thetape 232, or throughout the tape 232. The conductive tape 232 can bewrapped with a woven, stitch-bonded, or needle-punched tape. Theconductive fibers 234 can be commingled carbon fibers. The tape 232 canhave a plurality of commingled non-conductive fibers, which can be glassor aramid (kevlar). In addition, the conductive and/or non-conductivefibers can have thermoplastic filaments, in a composition of up to 50percent. The tape 232 can also include a plurality of commingledsynthetic fibers. The synthetic fibers can be polyester fibers, nylon,spectra, polyethylene or polyvinyl chloride. The non-conductive fibersand the synthetic fibers can enhance the bonding between the layers 222,224, 226 and the strength of the layers.

[0104] The flexible outer layer 226 is formed from extruding resin intoa generally cylindrical, or tubular shape. The resin in the outer layer226 is thermoplastic resin. Alternatively, the outer layer 226 can beformed from wrapping thermoplastic resin tape about an outer surface ofthe intermediate layer 224. The thermoplastic tape does not include anyconductive elements, and can be polyethylene or polyvinyl chloride. Thethermoplastic tape has excellent elongation properties and is lightweight. Therefore, the cost and weight of the composite pipe 210 isreduced. Also, the thermoplastic tape is generally thinner than extrudedresin and as a result, a thicker intermediate layer 224 can be utilized.

[0105] Referring to FIG. 15, the process equipment discloses a portionof the method for the in-line formation of the composite pipe 210 torepair a conduit. Resin, preferably thermoplastic resin, is injected tobegin the process. An extruder extrudes the thermoplastic resin to formthe inner layer 222, preferably in a cylindrical shape. A plurality ofconductive fibers 228 are overbraided, or wound about the flexible innerlayer 222 to form a discrete intermediate layer 224. The flexibleintermediate layer 224 is formed in close proximity to the outer surfaceof the inner layer 222. In addition to conductive fibers 228, theintermediate layer 224 can have a plurality of non-conductive fibers 230filament-wound therein. Alternatively, the intermediate layer 224 can beformed from conductive tape 232, which can be wrapped, filament-wound,weaved, stitch-bonded, or needle-punched. Next, thermoplastic resin isextruded to form a flexible outer layer 226. Alternatively, the outerlayer 226 can be formed from wrapping thermoplastic tape about an outersurface of the intermediate layer 224. Once these steps are completed, aflexible multi-component pipe 220 is formed. The pipe 220 can be cooledusing inline coolers. A device for pulling the pipe 220 advances thepipe 220 to a point where pressure can be applied to by a heateddeformer to deform the cross-sectional area of the pipe 220. Because thepipe 220 is formed from flexible layers 222, 224, 226, it can bedeformed partially, or completely.

[0106] The deformed pipe 220 is then spooled onto a storage spool, orcoil. This means that the deformed pipe 220 is wrapped about the spool.Since the pipe 220 is deformed, it consumes less space on the spool anda greater length of pipe 220 can be spooled on the spool. For example, aone-thousand foot length of deformed pipe 220 can be spooled.Alternatively, shorter lengths of pipe 220 can be spooled by employing ameans for cutting the pipe 220 into shorter segments.

[0107] Once the spool is transported to a jobsite for repairing adamaged conduit, the pipe 220 can be dispensed or inserted into thedamaged conduit. In its present state, the configurations of thedeformed pipe 220 do not correspond or match the internal configurationsof the damaged conduit. After the pipe 220 is properly positioned in theconduit, fluid pressure is applied to the pipe 220 to reshape the pipe220. The fluid pressure can be compressed air, or a liquid, i.e. hotwater or steam. While fluid pressure is being applied to the pipe 220,current is applied to the conductive fibers 228. The current resistivelyheats the conductive fibers 228 and heat forms and consolidates thelayers 222, 224, 226. Described in a different manner, the currentresistively heats the conductive fibers 228 past the melt temperature ofthe thermoplastic resin to consolidate the layers 222, 224, 226.

[0108] Electric leads can be connected to a power source and theconductive fibers 228 to supply the current. It has been found that0.5-1.0 amps per bundle of conductive fibers 228 is sufficient to heatform the layers 222, 224, 226. Alternatively, using 5 volts per foot(lengthwise) of the pipe 220 is suitable to cure the resin.

[0109] Once a sufficient amount of current is applied to the conductivefibers 228, the layers 222, 224, 226 consolidate and the composite pipe210 results. Described in a different manner, the composite pipe 210 isformed after the layers 222, 224, 226 are fully consolidated, or“tie-plied” into a single, integral unit. Prior to the formation of thecomposite pipe 210, the multi-component pipe 220 has multiple discretelayers 222, 224, 226. Although the composite pipe 210 is tie-plied, theinternal elements, such as the conductive fibers and non-conductivefibers, remain in the composite pipe 210.

[0110] Additional pressure can be applied to the composite pipe 210 tofurther reshape the composite pipe 210 to correspond to the innerdimensions of the conduit and to conform to the inner surface of theconduit. Described in a different manner, additional pressure is appliedto the composite pipe 210 such that it is intimate contact with theinner surface of the conduit. At that point, the composite pipe 210lines the conduit and effectively repairs the damaged portion of theconduit. The pressure applied to reshape can vary between 3 to 40 psig.

[0111] The application of current and additional pressure can be done ina generally simultaneous step. Accordingly, the layers 222, 224, 226 canbe consolidated to form the composite pipe 210 as the additionalpressure forces the pipe 210 into intimate contact with the innersurface of the conduit.

[0112] An alternative composite pipe 210 has an intermediate layer 224formed from a plurality of commingled conductive fibers 228 containingup to 50 percent thermoplastic fibers or filaments. Also, theintermediate layer 224 can have a plurality of commingled non-conductivefibers 230 containing up to 50 percent thermoplastic fibers orfilaments. The conductive fibers 228 and non-conductive fibers 230 canbe woven, stitch-bonded, braided, or knitted to form the intermediatelayer 224.

[0113] Generally, the conductive fibers 228 and non-conductive fibers230 have a tubular shape, and are covered with a thermoplastic film witha thickness up to 300 mills. Multiple layers of the conductive fibers228 and non-conductive fibers 230 can be combined or plied together toform the intermediate layer 224. The resulting intermediate layer 224and the multi-component pipe 220 are very flexible. As shown in FIG. 16,the intermediate layer 224 is so flexible and pliable that themulti-component pipe 220 virtually collapses or sags. Accordingly, themulti-component pipe 220 is does not require deformation and is easilyspooled onto a storage coil. Therefore, a separate deforming element isnot required.

[0114] The multi-component pipe 220 is used to repair a damaged conduitin a similar manner as described above. That means that fluid pressureis applied to reshape the multi-component pipe 220 and current isapplied to the conductive fibers 228 to heat form and consolidate thelayers 222, 224, 226 into an integral composite pipe 210.

[0115] A further alternate method involves forming a spoolable compositepipe 210 to be placed in a trench dug in the ground. There is noexisting conduit in the trench, and the finished composite pipe 210functions as a conduit. The finished composite pipe 210 can be employedas a conduit. The method includes the following steps, which are alsodiscussed above: extruding resin (thermoplastic or copolymer) to form aninner layer 222; winding a plurality of conductive fibers 228, orconductive tape 232 to form an intermediate layer 224, the intermediatelayer positioned about the inner layer 222; extruding resin, or wrappingthermoplastic tape to form an outer layer 226, the outer layer 226positioned about the intermediate layer 224 to form a flexiblemulti-component pipe 220; applying pressure to deform themulti-component pipe 220; and, spooling the multi-component pipe 220onto a storage coil. The multi-component pipe 220 is dispensed from thestorage coil into a trench, which is formed from the removal of soil andother materials from the ground. Fluid pressure is applied to themulti-component pipe 220 to reshape the multi-component pipe 220.Current is applied to the conductive fibers 228 in the multi-componentpipe 220 to resistively heat and consolidate the layers 222, 224, 226 toform the composite pipe 210. Additional fluid pressure is applied tofurther reshape the composite pipe 210 to a finished configuration. Thefinished configuration of the composite pipe 210 permits the pipe 210 tofunction as a conduit.

[0116] A still further alternate apparatus involves a spoolablecomposite pipe 250 to repair a damaged conduit, where the composite pipe250 is formed from a plurality of individual sheets. Referring to FIG.17, the multi-component pipe 260 includes a flexible, first sheet ofextruded thermoplastic resin. The first sheet is generally flat orplanar, and has a thickness ranging between 3 to 300 mills. The firstsheet is deformed about a mandrel to form a cylindrical inner layer 262.Alternately, the pipe 260 could include a flexible, first film (orplurality of films) of thermoplastic resin, either extruded orblow-molded. The first film could be generally flat or tubular, and havea thickness ranging from 3 to 300 mills.

[0117] An intermediate layer 264 is formed from winding a plurality ofconductive fibers 266 about an outer surface of the inner layer 262.Alternatively, conductive tape can be positioned about the outer surface261 of the inner layer 262 to form an intermediate layer 264. Theconductive tape can be wrapped, weaved, stitch-bonded, orneedle-punched. The conductive tape can have a plurality of conductivefibers 266.

[0118] A flexible, second sheet of thermoplastic resin is extruded. Thesecond sheet is generally flat and deformed about an outer surface ofthe intermediate layer 264 to form an outer layer 268. The second sheethas a thickness ranging from 3 to 300 mills. Alternatively,thermoplastic tape can be positioned about the outer surface of theintermediate layer 264 to form the outer layer 268. The thermoplastictape can be wrapped, weaved, stitch-bonded, or needle-punched.

[0119] The conductive fibers 266 can be commingled carbon fibers. Theintermediate layer 264 can include a plurality of comminglednon-conductive fibers, which can be glass or aramid (kevlar). Inaddition, the conductive and/or non-conductive fibers can havethermoplastic filaments, in a composition of up to 50 percent. Theintermediate layer 264 can also include a plurality of commingledsynthetic fibers. The synthetic fibers can be polyester fibers, nylon,spectra, polyethylene or polyvinyl chloride. To further increase thestrength and rigidity of the finished composite pipe 250, an additionallayer 270 or layers can be added between the layers 262, 264, 268.

[0120] A composite pipe 250 for repairing a damaged conduit can beformed from the generally flat sheets used in the multi-component pipe260. The formation of the composite pipe 250 comprises the followingsteps. Extruding a first sheet of curable thermoplastic resin. The firstsheet is generally flat and has a thickness ranging from 3 to 300 mills.Deforming the first sheet about a mandrel to form a cylindrical innerlayer 262 of the multi-component pipe 260. The deformation can be theresult of fluid pressure or other similar forces producing deformation.A plurality of conductive fibers 266 are wound about an outer surface ofthe inner layer 262 to form an intermediate layer 264 of themulti-component pipe 260. Alternatively, a conductive tape can bepositioned about the outer surface of the inner layer 262. Theconductive tape can be wrapped, weaved, stitch-bonded, orneedle-punched. The conductive tape can have a plurality of conductivefibers.

[0121] A second sheet of curable thermoplastic resin is extruded. Thesecond sheet is generally flat and has a relatively small thickness. Thesecond sheet is deformed about an outer surface of the intermediatelayer 264 to form an outer layer 268 of the multi-component pipe 260.Alternatively, thermoplastic tape can be positioned about the outersurface of the intermediate layer 264 to form the outer layer 268. Thethermoplastic tape can be wrapped, weaved, stitch-bonded, orneedle-punched. Pressure is applied to deform the multi-component pipe260, and then the pipe 260 is spooled onto a storage coil. Once thestorage coil is transported to a job site, where the damaged conduit islocated, the multi-component pipe is dispensed from the storage coilinto the damaged portion of the conduit. In its present state, theconfigurations of the spooled multi-component pipe 260 do not correspondwith or match the internal configurations of the damaged conduit. Afterthe pipe 260 is properly positioned in the damaged conduit, fluidpressure is applied to the multi-component pipe 260 to reshape the pipe260. The fluid pressure can be compressed air, or a liquid, i.e. hotwater or steam.

[0122] While fluid pressure is being applied to the pipe 260, current isapplied to the conductive fibers. The current resistively heats theconductive fibers 266 and heat forms the layers 262, 264, 268. Electricleads can be connected to a power source and the conductive fibers 266to supply the current. It has been found that 0.5-1.0 amps per bundle ofconductive fibers is sufficient to cure the resin. Alternatively, using5 volts per foot (lengthwise) of the pipe is suitable to cure the resin.

[0123] Once a sufficient amount of current is applied to the conductivefibers 266, the layers 262, 264, 268 consolidate and the composite pipe250 is formed. Described in a different manner, the composite pipe 250is formed after the layers 262, 264, 268 are fully consolidated into asingle, integral unit. Prior to the formation of the composite pipe 250,the multi-component pipe 260 has multiple discrete layers 262, 264, 268.

[0124] Additional pressure can be applied to the composite pipe 250 tofurther reshape the composite pipe 250 to correspond to the innerdimensions of the conduit and lines the conduit. Described in adifferent manner, additional pressure is applied to the composite pipe250 such that it is intimate contact with the inner surface of theconduit. At that point, the composite pipe 250 lines the conduit andeffectively repairs the damaged portion of the conduit. The pressureapplied to reshape can vary between 3 to 40 psig.

[0125] The application of current and additional pressure can be done ina generally simultaneous step. Accordingly, the layers 262, 264, 268consolidate to form the composite pipe 250 as the additional pressureforces the composite pipe 250 into intimate contact with the innersurface of the conduit.

[0126] While specific embodiments have been illustrated and described,numerous modifications are possible without departing from the spirit ofthe invention, and the scope of protection is only limited by the scopeof the accompanying claims.

We claim:
 1. An apparatus for repairing an intersection between a firstconduit and a second conduit comprising: a body to transport repairmaterial containing a heat curable resin to an intersection of a firstconduit and a second conduit; an inflation device carried by said body,said inflation device capable of compressing said repair material to atleast a portion of said intersection, said inflation device includingconductive fibers capable of electrically resistively heating saidinflation device to effect curing of said resin in said repair material.2. The apparatus of claim 1 wherein said conductive elements arenonferrous.
 3. The apparatus of claim 1 wherein said inflation devicecomprises an inflatable bladder.
 4. The apparatus of claim 1 furthercomprising a first caul plate connected to said body, said first caulplate moveable from a retracted position to an extended position tocompress a portion of said repair material against said first conduit toform a flange proximate said intersection.
 5. The apparatus of claim 4comprising a second caul plate connected to said body, said second caulplate moveable from a retracted position to an extended position tocompress a portion of said repair material against said first conduit toform a flange proximate said intersection.
 6. The apparatus of claim 4wherein said first caul plate comprises conductive fibers capable ofelectrically resistively heating said first caul plate.
 7. The apparatusof claim 5 wherein said second caul plate comprises conductive fiberscapable of electrically resistively heating said second caul plate. 8.The apparatus of claim 1 further comprising skid plates connected tosaid body.
 9. The apparatus of claim 1 wherein said body furthercomprises a lift cylinder to facilitate positioning of the repairmaterial against said intersection.
 10. An apparatus for repairing anintersection of a first conduit and a second conduit comprising asupport structure for transporting and positioning a repair materialimpregnated with a heat curable resin at an intersection of a firstconduit and a second conduit, said support structure housing aninflatable bladder having a plurality of conductive fibers forelectrically generating resistive heat to facilitate curing of saidresin impregnated in said material.
 11. The apparatus of claim 10further comprising a first line connected to said support structure forproviding fluid pressure from a source of fluid pressure to inflate saidbladder.
 12. The apparatus of claim 11 further comprising a second lineconnected to said support structure for providing electrical energy froma power source to said conductive fibers in said bladder.
 13. Theapparatus of claim 10 further comprising a wing formation connected tosaid support structure to compress a flange portion of said repairmaterial at said intersection.
 14. The apparatus of claim 13 furthercomprising conductive fibers in said wing portion for electricallygenerating resistive heat to facilitate curing of said flange portion ofsaid repair material.
 15. The apparatus of claim 10 further comprising alift mechanism to facilitate positioning of said repair material at saidintersection.
 16. A method of repairing an intersection of a firstconduit and a second conduit comprising the steps of: providing a repairmaterial configured to conform to an intersection of a first conduit anda second conduit; impregnating said repair material with a heat curableresin; positioning said repair material at said intersection;compressing said repair material against said intersection with astructure having a plurality of electrically conductive fibers; and,applying an electric current to said conductive fibers to resistivelyheat said fibers to facilitate curing of said resin in said repairmaterial.
 17. The method of claim 16 further comprising: providing aninflatable bladder for compressing said repair material against saidintersection; and, inflating said bladder.
 18. The method of claim 18further comprising: forming a flange in said repair material; and,compressing said flange against a portion of said first conduitproximate said intersection.
 19. A liner for repairing damage in largediameter conduits, the liner comprising: a plurality of discrete heatingzones, each zone impregnated with a curable resin, each zone having afiber architecture, the fiber architecture having a plurality ofconductive fibers; and, a plurality of interface areas, each interfacearea located between a pair of zones, each interface area impregnatedwith a curable resin, each interface area having a seam and a fiberarchitecture, the fiber architecture having a plurality ofnon-conductive fibers.
 20. The liner of claim 19 wherein the fiberarchitecture of each heating zone further comprises a plurality ofnon-conductive fibers.
 21. The liner of claim 19 wherein each interfacearea has a plurality of cavities.
 22. The liner of claim 19 furthercomprising means for sealing the interface areas and a portion of thezones.
 23. The liner of claim 22 wherein the sealing means is a hybridtape having a plurality of layers formed from non-conductive fibers anda layer formed from conductive fibers.
 24. The liner of claim 22 whereinthe sealing means is a hybrid tape having an outer layer formed fromnon-conductive fibers and an inner layer formed from conductive fibers.25. The liner of claim 22 wherein the sealing means is a hybrid tapehaving a first and a second layer formed from dielectric fibers and athird layer formed from conductive fibers, the third layer locatedbetween the first and second layers.
 26. The liner of claim 23 whereinthe sealing means is laminated to each heating zone proximate theinterface area.
 27. The liner of claim 23 wherein the sealing means isfused to each heating zone proximate the interface area.
 28. The linerof claim 23 wherein the sealing means is consolidated to each heatingzone proximate the interface area by heat and pressure.
 29. The liner ofclaim 19 including a plurality of electric leads, each lead connected toa heating zone.
 30. A liner for repairing damage in large diameterconduits, the liner comprising: a plurality of discrete heating zones,each zone having a fiber architecture impregnated with a curable resin,the fiber architecture having a plurality of conductive fibers; and, aplurality of interface areas, each interface area located between a pairof heating zones, each interface area having a fiber architectureimpregnated with a curable resin, the fiber architecture having aplurality of non-conductive fibers, the non-conductive fibers forming adielectric cavity.
 31. The liner of claim 30 wherein the fiberarchitecture of each heating zone further comprises a plurality ofnon-conductive fibers.
 32. The liner of claim 30 further comprisingmeans for sealing the interface areas, the sealing means affixed to aportion of the heating zones proximate the interface area.
 33. The linerof claim 32 wherein the sealing means is a hybrid tape having a pair ofouter layers formed from non-conductive fibers and an inner layer formedfrom conductive fibers.
 34. The liner of claim 30 including a pluralityof electric leads, each lead connected to a heating zone.
 35. A materialfor repairing damage in large diameter conduits, the materialcomprising: a liner having a plurality of discrete heating zones and aplurality of interface areas; each heating zone impregnated with acurable resin, each heating zone having a fiber architecture, the fiberarchitecture having a plurality of conductive fibers; each interfacearea located between adjacent zones, each interface area impregnatedwith a curable resin; each interface area having a seam and a fiberarchitecture, the fiber architecture having a plurality ofnon-conductive fibers; and, a tape affixed to an outer surface of eachinterface area.
 36. The material of claim 35 wherein the non-conductivefibers in each interface area form a cavity.
 37. The material of claim35 wherein the tape includes a pair of outer layers formed fromnon-conductive fibers and an inner layer formed from conductive fibers.38. The material of claim 35 including a plurality of electric leads,each lead connected to a heating zone.
 39. A method for repairing largediameter conduits, comprising the steps of: providing a liner having afirst and a second heating zone, each zone impregnated with a curableresin, each zone having a fiber architecture, the fiber architecturehaving a plurality of conductive fibers and non-conductive fibers; aplurality of interface areas, each interface area located between a pairof zones, each interface area impregnated with a curable resin, eachinterface area having a seam and a fiber architecture, the fiberarchitecture having a plurality of non-conductive fibers; applyingcurrent to the conductive fibers in the first heating zone to cure theresin therein; and, applying current to the conductive fibers in thesecond heating zone to cure the resin therein.
 40. The method of claim39 further comprising the step of providing a tape to seal the interfacearea, the tape having a plurality of conductive fibers and a pluralityof non-conductive fibers.
 41. The method of claim 40 further comprisingthe step of applying current to the tape to cure the resin in theinterface area.
 42. A method for repairing large diameter conduits,comprising the steps of: providing a liner having a lower and an upperheating zone, each zone impregnated with a curable resin, each zonehaving a fiber architecture, the fiber architecture having a pluralityof conductive fibers and non-conductive fibers; a plurality of interfaceareas, each interface area located between a pair of zones, eachinterface area impregnated with a curable resin, each interface areahaving a seam and a fiber architecture, the fiber architecture having aplurality of non-conductive fibers; a plurality of electric leads, eachlead connected to the conductive fibers in a heating zone; positioningthe liner within the conduit to be repaired; applying current to theconductive fibers in the lower heating zone to cure the resin therein;applying current to the conductive fibers in the upper heating zone tocure the resin therein; and, removing the electric leads from the linerafter the resin has cured.
 43. The method of claim 42 further comprisingthe step of providing a hybrid tape to seal the seam.
 44. Amulti-component pipe for use in repairing damaged conduit, the pipecomprising: an inner layer of thermoplastic resin, the inner layerformed from an extrusion process; an outer layer of thermoplastic resin,the outer layer formed from an extrusion process; and, an intermediatelayer having a fiber architecture, the fiber architecture formed fromwinding a plurality of conductive fibers.
 45. The multi-component pipeof claim 44 wherein the conductive fibers are carbon fibers.
 46. Themulti-component pipe of claim 45 wherein the fiber architecture includesa plurality of non-conductive fibers.
 47. The multi-component pipe ofclaim 46, wherein the conductive fibers and the non-conductive fibersare commingled with a plurality of thermoplastic filaments.
 48. Amulti-component pipe for use in repairing damaged conduit, the pipecomprising: an inner layer of thermoplastic resin, the inner layerformed from an extrusion process; an outer layer of thermoplastic resin,the outer layer formed from an extrusion process; and, an intermediatelayer formed from conductive tape, the conductive tape having aplurality of conductive fibers.
 49. The multi-component pipe of claim 48wherein the conductive tape is wrapped about an outer surface of theinner layer.
 50. The multi-component pipe of claim 48 wherein theconductive tape is woven about an outer surface of the inner layer. 51.The multi-component pipe of claim 48 wherein the conductive tape isstitch-bonded about an outer surface of the inner layer.
 52. Themulti-component pipe of claim 48 wherein the conductive tape isneedle-punched about an outer surface of the inner layer.
 53. Themulti-component pipe of claim 48 wherein the conductive fibers arecarbon fibers.
 54. The multi-component pipe of claim 48 wherein theintermediate layer further comprises a plurality of thermoplasticfibers.
 55. The multi-component pipe of claim 48 wherein theintermediate layer further comprises a plurality of non-conductivefibers, the non-conductive fibers commingled with plurality ofthermoplastic filaments.
 56. A method of repairing a damaged conduitwith a composite pipe, comprising the steps of: extruding thermoplasticresin to form an inner layer of a pipe; winding a plurality ofconductive fibers to form an intermediate layer, the intermediate layerpositioned about the inner layer; extruding thermoplastic resin to forman outer layer, the outer layer positioned about the intermediate layerto form a flexible multi-component pipe; applying pressure to deform themulti-component pipe; spooling the multi-component pipe onto a storagecoil; dispensing the multi-component pipe from the storage coil into adamaged conduit, the conduit having internal dimensions; applying fluidpressure to the multi-component pipe to reshape the multi-componentpipe; applying current to the conductive fibers in the multi componentpipe to heat form and consolidate the inner, intermediate, and outerlayers into a composite pipe; and, applying additional fluid pressure tofurther reshape the composite pipe to correspond to the internaldimensions of the conduit.
 57. The method of claim 56 further comprisingthe step of connecting electric leads to a power source and theconductive fibers in the composite pipe.
 58. A method of forming acomposite pipe to be placed in a trench dug in the ground, comprisingthe steps of: extruding thermoplastic resin to form an inner layer;winding a plurality of conductive fibers to form an intermediate layer,the intermediate layer positioned about the inner layer; extrudingthermoplastic resin to form an outer layer, the outer layer positionedabout the intermediate layer to form a flexible multi-component pipe;applying pressure to deform the multi-component pipe; spooling themulti-component pipe onto a storage coil; dispensing the multi-componentpipe from the storage coil into a trench; applying fluid pressure to themulti-component pipe to reshape the multi-component pipe; applyingcurrent to the conductive fibers in the multi-component pipe toconsolidate the inner, intermediate, and outer layers into a compositepipe; and, applying additional fluid pressure to further reshape thecomposite pipe to a finished configuration.
 59. The method of claim 58further comprising the step of connecting electric leads to a powersource and the conductive fibers in the composite pipe.
 60. A method offorming a multi-component pipe for use in a damaged conduit, comprising:extruding a first sheet of thermoplastic resin; deforming the firstsheet about a mandrel to form a cylindrical inner layer; winding aplurality of conductive fibers about an outer surface of the inner layerto form an intermediate layer; extruding a second sheet of thermoplasticresin; and, deforming the second sheet about an outer surface of theintermediate layer to form an outer layer.
 61. The multi-component pipeof claim 60 wherein the conductive fibers are carbon fibers.
 62. Themulti-component pipe of claim 60 wherein the intermediate layer includesa plurality of non-conductive fibers.
 63. A method of forming amulti-component pipe for use in a damaged conduit, comprising: extrudinga first sheet of thermoplastic resin; deforming the first sheet about amandrel to form a cylindrical inner layer; wrapping a conductive tapeabout an outer surface of the inner layer to form an intermediate layer,the conductive tape having a plurality of conductive fibers; extruding asecond sheet of thermoplastic resin; and, deforming the second sheetabout an outer surface of the intermediate layer to form an outer layer.64. The multi-component pipe of claim 63 wherein the conductive fibersare carbon fibers.
 65. The multi-component pipe of claim 63 wherein theintermediate layer further comprises a plurality of thermoplasticfibers.
 66. The multi-component pipe of claim 63 wherein theintermediate layer further comprises a plurality of non-conductivefibers, the non-conductive fibers commingled with a plurality ofthermoplastic fibers.
 67. A method of forming a composite pipe for usein a damaged conduit, comprising: extruding a first sheet ofthermoplastic resin; deforming the first sheet about a mandrel to form acylindrical inner layer of a multi-component pipe; winding a pluralityof conductive fibers about an outer surface of the inner layer to forman intermediate layer of the multi-component pipe; extruding a secondsheet of thermoplastic resin; deforming the second sheet about an outersurface of the intermediate layer to form an outer layer of themulti-component pipe; applying pressure to deform the multi-componentpipe; spooling the composite pipe onto a storage coil; dispensing themulti-component pipe from the storage coil into a damaged conduit, theconduit having internal dimensions; applying fluid pressure to themulti-component pipe to reshape the multi-component pipe; applyingcurrent to the conductive fibers in the multi-component pipe to heatform and consolidate the inner, intermediate, and outer layers into acomposite pipe; and, applying additional fluid pressure to furtherreshape the composite pipe to correspond to the internal dimensions ofthe conduit.
 68. The composite pipe of claim 67 wherein the conductivefibers are carbon fibers.
 69. The composite pipe of claim 67 wherein theintermediate layer includes a plurality of non-conductive fibers.